Bats in the House or Attic: What Homeowners Should Know
Bats are helpful in the yard, eating large numbers of insects, but a colony in the attic or walls is a different story. Bats also come with special rules, so it helps to know the basics before anything is done.
Common signs
- Bats flying out at dusk from the same spot on the roof, a gable vent or behind a chimney.
- Guano (droppings) piling up below an entry point or in the attic. It looks like mouse droppings but crumbles into a powder.
- Dark, greasy stains around small gaps where bats squeeze in and out.
- Squeaking or rustling in walls or the attic, especially around dusk and dawn.
If a bat is in your living space
Bats are one of the main sources of rabies in the United States, and a bat bite can be very small and hard to notice. The CDC recommends that if a bat is found in a room with a sleeping person, a child, or someone who cannot say whether they were bitten, you contact your local health department or a doctor, and, if it can be done safely, keep the bat confined rather than releasing it so it can be tested. Do not touch a bat with bare hands.
Why timing and method matter
Many bat species are protected by state or federal law. In many states, bats may not be excluded during the summer maternity season, when young bats cannot yet fly and would be trapped inside. The usual method is exclusion: installing one-way devices so bats can leave at night but not return, then sealing the entry points once they are gone.
What you can do now
- Watch your house at dusk and note where bats come out.
- Keep children and pets away from guano and from any grounded bat.
- Do not use poisons or repellents; they are not an effective or legal fix for bats.